Cloning and Characterization of the rpfC Gene of Xanthomonas oryzae pv. oryzae: Involvement in Exopolysaccharide Production and Virulence to Rice. Ji-Liang Tang. (1) Laboratory of Molecular Genetics, Guangxi Agricultural University, Nanning, Guangxi 530005, P. R. China; (2) The Sainsbury Laboratory, John Innes Centre, Norwich NR4 7UH, U. K. Jia-Xun Feng(1,2), Qi-Qin Li (1), Hai-Xiang Wen (1), Dong-Lin Zhou (1), T. J. Greer Wilson (2), J. Maxwell Dow (2), Qing-Sheng Ma (1), and Michael J. Daniels(2). (1) Laboratory of Molecular Genetics, Guangxi Agricultural University, Nanning, Guangxi 530005, P. R. China; (2) The Sainsbury Laboratory, John Innes Centre, Norwich NR4 7UH, U. K. MPMI 9:664-666. Accepted 31 May 1996. Copy right 1996 The American Phytopathological Society.

rpfC is one of a cluster of genes which coordinately regulate the synthesis of extracellular enzymes and exopolysaccharide and pathogenicity in Xanthomonas campestris pv. campestris, the black rot pathogen of brassicas. An rpfC homolog which could functionally complement an rpfC mutant of X. campestris pv. campestris was identified in Xanthomonas oryzae pv. oryzae and the gene was characterized. Mutation of this gene in X. oryzae pv. oryzae had no effect on extracellular enzymes, but exopolysaccharide synthesis and virulence to rice were substantially reduced.